A conventional wheelchair comprises a chair frame with a seating area between two large drive wheels, as well as two smaller auxiliary wheels and foot rests in front of them. The drive wheels are on their outer side provided with a drive ring, which in turn is connected to the wheel rim. The drive rings are rotated with the hands, allowing independent locomotion without third party.
Since this locomotion requires a high degree of effort, a drive was proposed in DE-U 202010005729, which would allow a power-saving and safe handling. This is done by a drive lever which is hinged to the wheel axles of the drive wheels and can be swung back and forth about the wheel axis. The drive levers reach out over the radius of the drive wheel and are provided with a handle and a brake. The pivotal movement of a drive lever is limited by an extension arm guided in a longitudinal slot of a protection plate.
In DE-U-202008017474, a drive motor is arranged in the axis of the drive wheels, to support the manual driving force, wherein a control device is provided, which comprises an anti-back-roll mode of operation.
In a similar solution according to DE-U-202007008736, each drive wheel is part of a drive wheel module with a drive power unit arranged in the body frame of the wheelchair, in order to minimize the width of the wheelchair.
In order to move forward, the person seated in the wheelchair must use at least one hand to rotate a drive ring of a drive wheel and/or operate the control device of a drive power unit.